Problem Statement

Bowling pins are numbered 1 through 10. The following figure is a top view of the arrangement of the pins:

Let us call each part between two dotted lines in the figure a column.
For example, Pins 1 and 5 belong to the same column, and so do Pin 3 and 9.

When some of the pins are knocked down, a special situation called split may occur.
A placement of the pins is a split if both of the following conditions are satisfied:

• Pin 1 is knocked down.
• There are two different columns that satisfy both of the following conditions:
  • Each of the columns has one or more standing pins.
  • There exists a column between these columns such that all pins in the column are knocked down.

See also Sample Inputs and Outputs for examples.

Now, you are given a placement of the pins as a string S of length 10. For i = 1, \dots, 10, the i-th character of S is 0 if Pin i is knocked down, and is 1 if it is standing.
Determine if the placement of the pins represented by S is a split.

Constraints

• S is a string of length 10 consisting of 0 and 1.

Sample Input 1

0101110101

Sample Output 1

Yes

In the figure below, the knocked-down pins are painted gray, and the standing pins are painted white:

Between the column containing a standing pin 5 and the column containing a standing pin 6 is a column containing Pins 3 and 9. Since Pins 3 and 9 are both knocked down, the placement is a split.

Sample Input 2

0100101001

Sample Output 2

Yes

Sample Input 3

0000100110

Sample Output 3

No

This placement is not a split.

Sample Input 4

1101110101

Sample Output 4

No

This is not a split because Pin 1 is not knocked down.

Problem Statement

Takahashi has N foods in his house. The i-th food has the tastiness of A_i.
He dislikes K of these foods: for each i=1,2,\ldots,K, he dislikes the B_i-th food.

Out of the foods with the greatest tastiness among the N foods, Takahashi will randomly choose one and eat it.
If he has a chance to eat something he dislikes, print Yes; otherwise, print No.

Constraints

• 1\leq K\leq N\leq 100
• 1\leq A_i\leq 100
• 1\leq B_i\leq N
• All B_i are distinct.
• All values in input are integers.

Sample Input 1

5 3
6 8 10 7 10
2 3 4

Sample Output 1

Yes

Among the five foods, the ones with the greatest tastiness are Food 3 and 5, of which he eats one.
He dislikes Food 2, 3, and 4, one of which he has a chance to eat: Food 3.
Therefore, the answer is Yes.

Sample Input 2

5 2
100 100 100 1 1
5 4

Sample Output 2

No

The foods with the greatest tastiness are Food 1, 2, and 3, none of which he has a chance to eat.

Sample Input 3

2 1
100 1
2

Sample Output 3

No

The food with the greatest tastiness is Food 1, which he has no chance to eat.

Problem Statement

There is a 10^9-story building with N ladders.
Takahashi, who is on the 1-st (lowest) floor, wants to reach the highest floor possible by using ladders (possibly none).
The ladders are numbered from 1 to N, and ladder i connects the A_i-th and B_i-th floors. One can use ladder i in either direction to move from the A_i-th floor to the B_i-th floor or vice versa, but not between other floors.
Takahashi can freely move within the same floor, but cannot move between floors without using ladders.
What is the highest floor Takahashi can reach?

Constraints

• 1 \leq N \leq 2 \times 10^5
• 1 \leq A_i, B_i \leq 10^9
• A_i \neq B_i
• All values in the input are integers.

Sample Input 1

4
1 4
4 3
4 10
8 3

Sample Output 1

10

He can reach the 10-th floor by using ladder 1 to get to the 4-th floor and then ladder 3 to get to the 10-th floor.

Sample Input 2

6
1 3
1 5
1 12
3 5
3 12
5 12

Sample Output 2

12

Sample Input 3

3
500000000 600000000
600000000 700000000
700000000 800000000

Sample Output 3

1

He may be unable to move between floors.

Problem Statement

We have HW cards arranged in a matrix with H rows and W columns.
For each i=1, \ldots, N, the card at the A_i-th row from the top and B_i-th column from the left has a number i written on it. The other HW-N cards have nothing written on them.

We will repeat the following two kinds of operations on these cards as long as we can.

• If there is a row without a numbered card, remove all the cards in that row and fill the gap by shifting the remaining cards upward.
• If there is a column without a numbered card, remove all the cards in that column and fill the gap by shifting the remaining cards to the left.

Find the position of each numbered card after the end of the process above. It can be proved that these positions are uniquely determined without depending on the order in which the operations are done.

Constraints

• 1 \leq H,W \leq 10^9
• 1 \leq N \leq \min(10^5,HW)
• 1 \leq A_i \leq H
• 1 \leq B_i \leq W
• All pairs (A_i,B_i) are distinct.
• All values in input are integers.

Sample Input 1

4 5 2
3 2
2 5

Sample Output 1

2 1
1 2

Let * represent a card with nothing written on it. The initial arrangement of cards is:

*****
****2
*1***
*****

After the end of the process, they will be arranged as follows:

*2
1*

Here, the card with 1 is at the 2-nd row from the top and 1-st column from the left, and the card with 2 is at the 1-st row from the top and 2-nd column from the left.

Sample Input 2

1000000000 1000000000 10
1 1
10 10
100 100
1000 1000
10000 10000
100000 100000
1000000 1000000
10000000 10000000
100000000 100000000
1000000000 1000000000

Sample Output 2

1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
10 10

Problem Statement

This is an interactive task, where your program and the judge interact via Standard Input and Output.

The judge has a string of length N consisting of 0 and 1: S = S_1S_2\ldots S_N. Here, S_1 = 0 and S_N = 1.

You are given the length N of S, but not the contents of S. Instead, you can ask the judge at most 20 questions as follows.

• Choose an integer i such that 1 \leq i \leq N and ask the value of S_i.

Print an integer p such that 1 \leq p \leq N-1 and S_p \neq S_{p+1}.
It can be shown that such p always exists under the settings of this problem.

Constraints

• 2 \leq N \leq 2 \times 10^5

Input and Output

First, receive the length N of the string S from Standard Input:

N

Then, you get to ask the judge at most 20 questions as described in the problem statement.

Print each question to Standard Output in the following format, where i is an integer satisfying 1 \leq i \leq N:

? i

In response to this, the value of S_i will be given from Standard Input in the following format:

S_i

Here, S_i is 0 or 1.

When you find an integer p satisfying the condition in the problem statement, print it in the following format, and immediately quit the program:

! p

If multiple solutions exist, you may print any of them.

Notes

• Print a newline and flush Standard Output at the end of each message. Otherwise, you may get a TLE verdict.
• If there is malformed output during the interaction or your program quits prematurely, the verdict will be indeterminate.
• After printing the answer, immediately quit the program. Otherwise, the verdict will be indeterminate.
• The string S will be fixed at the start of the interaction and will not be changed according to your questions or other factors.

Sample Input and Output

In the following interaction, N = 7 and S = 0010011.

For the presented p = 5, we have 1 \leq p \leq N-1 and S_p \neq S_{p+1}. Thus, if the program immediately quits here, this case will be judged as correctly solved.